This sample only works with Image services sub-layers that are renderered using a simple renderer.
The sample code searches for first ArcIMS Image service in the ArcMap document,
and extracts the first simple renderered sub-layer symbol to set the control properties in the form,
like: color, style, etc.

The sample covers:

Retrieve Image services from the current Map.

Retrieve the first simple renderered Image service sub-layer.

Get the renderer's symbol, and update controls properties in the form.

Change the sub-layer renderer.

Refresh dataview, and TOC.

How to use:

Bring the VBA Editor from the Tools menu, under Macros (Alt+F11)

Go to Tools, select References...

Select the Microsoft XML, version 2.0 reference (msxml.dll)

Bring the Customize dialog from the Tools menu in ArcMap.

Select the Commands tab, and scroll down in Categories, select UIControls, save it in Untitled, and click New UIControl...

The New UIControl use the default (UIButtonControl), and click Create and Edit button.